Brain Machine Interfaces (BMIs) are connections between a human brain and a computer that are meant to supplement and expand a person’s abilities. They have long been a subject of research in the medical field for their potential to help with the rehabilitation of quadriplegics, communication in ALS patients, and other areas. The technology is starting to attract serious attention now with Tesla’s CEO Elon Musk declaring he would have a working invasive BMI (involving a chip implanted directly in the brain) ready in four years, and Facebook announcing they are working on a device for typing text using a non-invasive BMI. What once seemed like a far-off future scenario suddenly appears to be within our grasp, and the internet is full of lively debates over the new possibilities—and dangers—that BMI could bring.

Still, those whose imaginations run wild at the thought of a world of “cyber brains”—where our brains are partially replaced by electronics and linked directly to external networks—only have to look to Japanese anime for clues. For instance, the movie “Paprika,” an animated film released in 2006 based on the novel by Yasutaka Tsutsui, is set in a world where BMI technology allows doctors to infiltrate their patients’ dreams and perform psychotherapy treatments. The story reveals the dangers involved in the abuse of this technology, which could blur the boundary between dream and reality and allow others to invade one’s mind. And “Ghost in the Shell,” which is said to have heavily influenced the Hollywood film “The Matrix,” is an even more sweeping and profound consideration of cyber-society.

For example, it depicts a fantasy world based on the idea that information in the brain can be partly or totally transferred to external memory (or vice versa, that outside information can be put in one’s brain)—a world where you have the option to “live on” by transferring your cerebral data to a robot if your body and mind decline, and where you can instantaneously master a foreign tongue by downloading language information. On the flip side, it’s considered commonplace for brains linked together over a network to communicate telepathically, and anyone with strong hacking skills can hijack other people’s brains and control them at will. The story shines in portraying both the convenience and the threat in a comprehensible way.

Will such a world truly become a reality? Elon Musk’s claim that it’s only four years away certainly has its share of skeptics. Doubters not only believe this will be difficult from a technical standpoint, but also see people’s resistance to having chips embedded in their brains as an impediment. But no one knows for sure. If they come out with a technique someday for implanting a small chip in an infant’s head that will supposedly make junior high entrance exams a breeze, there’s a good chance many parents will jump at the opportunity. The arrival of that anime-like world now seems surprisingly close at hand.